import 'package:flutter/material.dart';
void main () => runApp(MyApp());

class MyApp extends StatelessWidget{
  @override
  Widget build(BuildContext context ){
    return MaterialApp(
      title:'ListView widget',
      home:Scaffold(
          body:GridView(
            gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: 3,
                mainAxisSpacing: 2.0,
                crossAxisSpacing: 2.0,
                childAspectRatio: 0.7
            ),
            children: <Widget>[
              new Image.network('http://img5.mtime.cn/mt/2018/10/22/104316.77318635_180X260X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/10/10/112514.30587089_180X260X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/13/093605.61422332_180X260X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/07/092515.55805319_180X260X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/21/090246.16772408_135X190X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/17/162028.94879602_135X190X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/19/165350.52237320_135X190X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/16/115256.24365160_180X260X4.jpg',fit: BoxFit.cover),
              new Image.network('http://img5.mtime.cn/mt/2018/11/20/141608.71613590_135X190X4.jpg',fit: BoxFit.cover),

            ],
          )
      ),
    );
  }
}
// childAspectRatio:宽高比，这个值的意思是宽是高的多少倍，如果宽是高的2倍，那我们就写2.0，如果高是宽的2倍，我们就写0.5。
